At a surprise party for a friend you’ve tied a series of 20-cmdiameter helium balloons to a flagpole, each tied with a short string. The first one is tied 1 m above the ground, and the other eight are tied at 1 m spacings, so that the last is tied at a height of 9 m. You notice that in the steady wind, each balloon is blown by the wind so it looks like the angles that the strings make with the vertical are about 10°, 20°, 30°, 35°, 40°, 45°, 50°, 60°, and 65°. Estimate and plot the wind velocity profile for the 9-m range. Assume the helium is at 20°C and 10 kPa gage and that each balloon is made of 3 g of latex.
At a surprise party for a friend you’ve tied a series of 20-cmdiameter helium balloons to a flagpole, each tied with a short string. The first one is tied 1 m above the ground, and the other eight are tied at 1 m spacings, so that the last is tied at a height of 9 m. You notice that in the steady wind, each balloon is blown by the wind so it looks like the angles that the strings make with the vertical are about 10°, 20°, 30°, 35°, 40°, 45°, 50°, 60°, and 65°. Estimate and plot the wind velocity profile for the 9-m range. Assume the helium is at 20°C and 10 kPa gage and that each balloon is made of 3 g of latex.
At a surprise party for a friend you’ve tied a series of 20-cmdiameter helium balloons to a flagpole, each tied with a short string. The first one is tied 1 m above the ground, and the other eight are tied at 1 m spacings, so that the last is tied at a height of 9 m. You notice that in the steady wind, each balloon is blown by the wind so it looks like the angles that the strings make with the vertical are about 10°, 20°, 30°, 35°, 40°, 45°, 50°, 60°, and 65°. Estimate and plot the wind velocity profile for the 9-m range. Assume the helium is at 20°C and 10 kPa gage and that each balloon is made of 3 g of latex.
2.) We are on the space station, so there is no effective gravity. In a small fluid experiment, a small spherical bacteria of 1 mm radius is moving at a speed of +1.50 mm/second horizontally in the fluid. The bacteria has a density of 1500. kg/m^3.
(3a) Draw a free-body diagram, labeling all forces and show the likely direction of Fnet
(3b) What is the mass of the bacteria?
(3c) If the value of the viscosity is 1.25 kg/m/s, then what is the net acceleration experienced by the bacteria at that moment.
In a closed subway car, a girl holds a helium-filled balloon by a string. While the car is traveling at constant velocity, the string of the balloon is exactly vertical. (Hint: For constant velocity, a buoyant force acts upward, but for constant deceleration, the buoyant force becomes tilted, but remains antiparallel to the tension.)a) While the subway car is braking, will the string be inclined forward or backward relative to the car? b) Suppose that the string is inclined at an angle of 20° with the vertical and remains there. What is the acceleration of the car?
Use vectors to explain why it is difficult to hold a heavy stack of books perfectly still for a long period of time. As you become exhausted, what eventually happens? What does this mean in terms of the forces acting on the books?
Chapter 9 Solutions
Fox and McDonald's Introduction to Fluid Mechanics
Automotive Technology: Principles, Diagnosis, And Service (6th Edition) (halderman Automotive Series)
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